In a building having a pitched or sloping roof, there is often an attic. An example of this is a house, a garage, or a shop. In a house, and above the ceiling, there is an attic. In many houses there is a dead air space above the ceiling and below the roof or the sheeting for the roof. In the attic there is a dead air space because of no circulation or only a small amount of circulation.
In the summer there is a build-up of heat in the attic or an increase in the temperature in the attic. If there be a high humidity, then the rafters and ridgeboard in the attic may rot. In fact, the wooden trusses in the attic and even the sheeting for the roofing material may rot.
It is well known that the attic should be cool. A cool attic will help perserve the rafters, ridgeboards and wooden trusses.
Above the ceiling there can be placed insulation so that there is only a minimum of heat loss through the ceiling. However, above the insulation there should be air circulation so as to allow the attic to be cool. With air circulation there is a less possibility of an increase in temperature in the attic and build-up of heat. Also, with air circulation there is less possibility of an increase in humidity in the air in the attic.
In many of the older residential houses, there was no provision for air circulation in the attic. The air was trapped between the ceiling of the room, the sheeting underlying the roofing material and the ends of the residential house. As a result, in the summertime, there would be an increase in the temperature in the attic and there would be a possibility of the combination of the higher temperature and the humidity in the air for some rot to take place in the wooden trusses, rafters or ridge boards.
There have been many inventions in recent years relating to solving the problem of air circulation in the attic. In preparing this patent application, a patent search was made. The patents found in this patent search were four. One of these patents is Maze, U.S. Pat. No. 4,109,433, issuing date of 29, Aug. 1978. Maze teaches of a sheeting. There is an opening in the sheeting between rafters. There is an arcuate dome over the openings and screens over the ends of the arcuate dome. There is a funnel under the sheeting. This funnel leads upwardly toward the ridge of the roof. The funnel is supposed to conduct hot air near the ridge of the roof to the opening and out through the arcuate dome. Maze lists a number of patents cited in the prosecution of the patent application. In the Maze patent there are many separate parts. The separate parts must be assembled into the roof ventilator. It is expensive to assemble these separate parts into an appropriate roof ventilator.
Flanagan, U.S. Pat. No. 2,973,704, issue date of 7, Mar. 1961, teaches of a roof ventilator. This roof ventilator fits flush on a sloping roof. There are a number of inverted louvers. These louvers are directed upwardly. Underneath the louvers there is a bottom 20 which slopes downwardly. It is possible for air to enter into the space above the bottom 20 and below the louvers. The air can pass out through the louvers so there is air circulation. If water happens to pass through the louvers, the water drops onto the bottom 20 and flows downwardly and onto the roof. Again, Flanagan teaches of a complicated roof ventilator having many separate parts. There parts must be assembled into the roof ventilator. It is expensive to assemble the parts into the roof ventilator.
Katt et al, U.S. Pat. No. 2,954,727, issuing date of 4, Oct. 1960, teaches of a roof ventilator. There is an opening in the roof deck. The hood 15' covers the opening in the roof deck. There are downwardly directed louvers, having a screen 18 to keep out undesirable objects such as leaves, birds, small rodents and the like. Again, the hot air in the atitc flows upwardly and can pass through the opening in the roof and out of the roof ventilator so that there is air circulation in the attic. Again, Katt teaches of a complicated roof ventilator having many separate parts. It is necessary to assemble this roof ventilator. The assembling of the roof ventilator is expensive.
There is a patent Farren, U.S. Pat. No. 2,624,298, issuing date of 6, Jan. 1953. The reference Farren teaches of a tile roof structure having roof tile 10. There are openings in the roof tile to allow air to enter underneath the roof tile and flow upwardly over the underlying roof sheeting. Then, the air in flowing upwardly can flow out through an opening in a part near the upper tiles so as to allow air circulation over the roof sheeting and underneath the tile. It is to be noted that Farren does not teach of ventilation of an attic.
There are many types of roofs. A common type of roof is a roof having a ridge board and rafters. This is a sloping roof. If there is no means for allowing circulation of air in the attic underneath the roof there is a build-up of heat and an increase in the temperature of the air in the attic.
A second type of roof is a sloping roof using a truss for supporting the roof. The comments with respect to a ridge roof and a ridge board are also applicable with respect to a truss roof.
A third type of roof is a shed roof. With a shed roof there should be a means to allow the circulation of air in the attic in that space above the ceiling and below the shed roof.
It is desirable to prevent the accumulation and build-up of moisture in an attic. One of the ways to solve this is to have attic with air circulation in the attic. With adequate air circulation it is desirable to prevent air turbulance in the air in the attic. By allowing a reasonable amount of air to enter the attic and to leave the attic air turbulance can be prevented and also there can be achieved an adequate circulation of air in the attic.
One of the deleterious effects of moisture in air in the attic, a mixture of air and water vapor, is the reduction of the effectiveness in insulation. If there is too great an amount of moisture in the air in the attic, the insulation above the ceiling is not effective and there is a greater heat loss.